1. Field of the Invention
The present invention relates to a controller for adjusting the use of electric power at electric power facilities. In particular, it relates to means for coordinating an operation schedule with nearby customer equipment in order to maintain the quality of electric power in a power distribution network.
2. Background Art
Distributed power resources provided in customer equipment are normally operated in accordance with the demand from individual customers. In many cases, the method of operation, such as a base operation for high efficiency, a peak operation for lowering the contract demand, and a backup operation, is determined by the customer. When these distributed power resources are linked to an electric power system, a certain understanding is exchanged such that no adverse effect is experienced by the electric power system. The guidelines for such an understanding differ from country to country or depending on the operator of the electric power system. In any case, the individual customers with their individual electric power facilities are examined. As it is required that the quality of the electric power system not be disturbed in every possible state of operation of the distributed power resources, the customer might be demanded to furnish a phase modifying equipment or even the linkage itself might not be granted.
The operator of the electric power system must also equip the system with phase modifying equipment so that a predetermined power quality can be maintained no matter how the individual distributed power resources are operated. Under the premise that the distributed power resources are freely operated, the distributed power resources must be evaluated on the assumption that they are negative factors in terms of power quality, before their manner of installment is finalized.
On the other hand, from the viewpoint of power supply resources, there have been discussions about how effectively the effective power supplied by distributed power resources can be incorporated into the entire electric power system. For example, JP Patent Publication (Kokai) No. 2001-86645 discloses that by coordinating the methods of operating distributed power resources, an optimum power generating plan can be realized in a part of the power system or within a certain region. As the disclosed invention considers the problem in terms of effective power, the effect of such coordinated operation can be easily translated into monetary value.